The Rio Grande Rift

The Rio Grande Rift is the result of the northern portion of the Mexican land mass moving westward.  The northward pressure being applied by the subducting Cocos Plate on the southernmost Pacific coast of Mexico is causing the land mass to pivot on the central highlands heavy-spots.

The Rio Grande Rift is a north-south fracture in the earth's surface extending from Leadville, Colo., to Las Cruces, NM The 450 mile Rift was formed by the sinking of a large block of the earth's crust, creating a trough bounded  by mountains.

Here in the Rio Grande Rift we find much evidence that these pressures are both steady and current. The faults along which this downward motion occurred experience many small earthquakes establishing that the Rift is still actively growing.  Although it began to move upward about seven to ten million years ago, more recent geologic events such as the formation of volcanoes in the last 190,000 years have raised the ante in our bet against dramatic change. These volcanoes have emerged through the middle of the the rift, which has become a significant aquifer. A return to activity could be accompanied by explosive eruptions. In geological terms, the volcanos are recent, occurring in just the last fiftieth of the life of the rift.  

The seven to ten million years age of the Rio Grande Rift is similar to the age of the Grand Canyon  and the Gulf of California, both also products of the same set of forces driving the Mexican Disconnection.

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